Hi Ladies and Gents! first post here, but ive been reading on the sly for some time 
I was recently givin 3 mature angel fish from a friend who didnt want them anymore..
I'm aware that they are pretty aggressive fish, and dont take too kindly to other fish when they are matured/older then what they do when they are younger
But the thing is the two black angels are ganging up on the gold one and harrasing it like mad
Is it because he is gold? (IZ IT BCOZ I IZ GOLD?!) haha sorry..
or is it just because they are a pair and feel threatend by the other angel?
I have a 20Gal tank and it has no other fish in it.
I was recently givin 3 mature angel fish from a friend who didnt want them anymore..
I'm aware that they are pretty aggressive fish, and dont take too kindly to other fish when they are matured/older then what they do when they are younger
But the thing is the two black angels are ganging up on the gold one and harrasing it like mad

or is it just because they are a pair and feel threatend by the other angel?
I have a 20Gal tank and it has no other fish in it.